iOS: Taking a long road trip is often an expensive vacation, but if you're willing to offer up your free seats to strangers, Ridejoy is an iPhone app that lets you sell off the spare spots in your car to help someone get to where you're going.

Ridejoy is essentially a modernized version of hitchhiking. In the app, you can create a new trip, or start looking for people with spare seats in your area. When you create a trip, you enter in how many seats you have available, and how much you'd like to charge to get from point A to point B. Then, people will request a spot and you can vet them based on a simple profile or Facebook account. The same basic process works in reverse if you're looking for a ride as well. The service is new, but a lot of rides already exist. If you've ever wanted the experience of hitchhiking without the pain of standing on the side of the road, Ridejoy is worth checking out.